Hello friends, Recently I have a problem with the way we say "Speak of the devil!"

Besides "Talk of the Devil, and he is bound to appear," may I say "Speaking of the Devil, and he is bound to appear." Or "Speaking of the devil and the devil comes." Or"Speak of the devil and the devil comes." Or"Speaking of the devil, and here he is." Or"Speak of the devil, and here he is." Or"Speak of the Devil! Look who is here."In this case, should "d" in the word "devil" be a capital letter?